1. Field of the Invention
The present invention relates to a record mode setting apparatus for controlling a program recording operation by automatically actuating a recording means in response to a VPS code multiplexed on a broadcasting signal.
2. Description of the Prior Art
In West Germany, a program presetting system referred to as a VPS (video program system) has been widely used in a video tape recorder. The VPS is adapted such that timer recording of the video tape recorder can be controlled on the side of a broadcasting station when the broadcasting station superposes on a video signal a digitized code (VPS code) for identifying a program and broadcasts the same. The VPS is disclosed in detail in German Patent Laying-Open Gazette Nos. 2950432, 3243610 and the like.
Referring now to FIG. 1, description is made on an example of a conventional record mode setting apparatus using such a VPS.
Preset program information is input to a preset program storing circuit 6 by operation of a program preset button group 4. The preset program storing circuit 6 stores the preset program information as a preset program code and provides the same to display means 9, so that the display means displays the information. The preset program code includes a starting time code concerning the starting time point of recording, a channel code concerning a preset program channel, and an ending time code concerning the ending time point of recording (or a recording time period). The preset program storing circuit 6 also stores the set state of a VPS setting switch 5 for selecting a program preset mode. The program preset mode is set to a VPS program preset mode by turning the VPS setting switch 5 on and set to a normal program preset mode by turning the VPS setting switch 5 off. In the VPS program preset mode, a program is recorded in response to a VPS code multiplexed on a video signal independently of the starting time of recording and the ending time of recording as represented by the preset program code. In the normal program preset mode, the program is recorded from the starting time of recording to the ending time of recording in accordance with the actual time. The VPS code includes at least a program code showing the predicted starting time of a program.
In the VPS program preset mode, a before-three hours determining circuit 13 compares real-time information output from a clock circuit 11 with the starting time code stored in the preset program storing circuit 6 and starts operating a second power supply circuit 15 three hours, for example, before the starting time recording. Thus, a tuner 2 is driven. A channel selecting circuit 12 inputs a channel code stored in the preset program storing circuit 6 and applies a corresponding tuning voltage to the tuner 2. Thus, the tuner 2 selects a video signal corresponding to a preset program channel from a broadcasting signal obtained by an antenna 1 and applies the video signal to a VPS decoder 3. As a result, the VPS decoder 3 starts decoding the VPS code three hours before the starting time of recording and continues to send the same to a code latch circuit 7.
A preset program coincidence determining circuit 8 compares a program code included in the VPS code stored in the code latch circuit 7 with the starting time code stored in the preset program storing circuit 6 and outputs a coincidence signal when both coincide with each other. A timer control circuit 10 operates a first power supply circuit 14 in response to the coincidence signal. Thus, recording means 16 is driven by the power supply 14, so that recording of the video signal output from the tuner 2 is started. The recording is performed during a time period when the program code included in the above described VPS code continue to coincide with the starting time code included in the preset program code. Meanwhile, if the above described program code is changed to a code indicating interruption of the program (program interruption code), only the above described first power supply circuit 14 is not operated while the program interruption code is being produced. When the program during recording is ended, the program code included in the VPS code is changed, so that the coincidence signal is not output from the preset program coincidence determining circuit 8, resulting in ending of recording. Thus, in the VPS program preset mode, if the time for a desired program is changed and the time for a program is extended, the program can be surely recorded.
On the other hand, if the VPS code is not multiplexed on the video signal, the VPS code is not stored in the above described code latch circuit 7. When the preset program coincidence determining circuit 8 determines that the VPS code is not stored in the code latch circuit 7, recording is performed in the normal program preset mode.
In the normal program preset mode, the preset program coincidence determining circuit 8 compares the real-time information output from the clock circuit 11 with the starting time code stored in the preset program storing circuit 6 and outputs the coincidence signal when both coincide with each other. The timer control circuit 10 operates the first power supply circuit 14 and the second power supply circuit 15 in response to the coincidence signal. As a result, at the starting time of recording, recording is started. After recording is started, the preset program coincidence determining circuit 8 compares the real-time information output from the clock circuit 11 with the ending time code stored in the preset program storing circuit 6 and outputs the coincidence signal when both coincide with each other. The timer control circuit 10 stops operation of the first power supply circuit 14 and the second power supply circuit 15 in response to the coincidence signal and ends recording by recording means 16. Even if the VPS code is multiplexed on the video signal corresponding to the preset program channel, recording is performed in the above described normal program preset mode irrespective of the contents stored in the code latch circuit 7 if the VPS setting switch 5 is set to the off state at the time of program presetting operation.
In FIG. 1, the portion 20 enclosed by a broken line is structured by a microcomputer.
A video tape recorder comprising the above described record mode setting apparatus can perform not only the above described normal preset program recording but also manual recording.
The above described conventional record mode setting apparatus can not control recording based on the VPS code in the case of recording by normal manual operation, so that a user can not surely record a desired program if a user does not continue to monitor the program until the program is ended.